| 摘要 |
PURPOSE:To improve the degree of separation and group delay frequency characteristics, by using a waveguide whose size toward an electric field of a wave of a low frequency is <=1/2 of the wavelength of a wave of a high frequency and tapered, as a waveguide connected to a coupling hole branching the wave of the low frequency. CONSTITUTION:A wave of an electric field 5a is reflected on a short-circuit plate 3a between two orthogonal waves propagating in a main waveguide 1 and led to a connection waveguide 4a at a coupling hole 2a through magnetic field coupling. The wave of an electric field 5b generates a spurious mode (TM mode) at the coupling hole 2a. The size of the connection waveguide 4a toward the electric field 5a is taken as <=1/2 of the wavelength of the high frequency and a straight part 7 having a length of 1/4 wavelength is provided between the tapered part and the coupled part. Then, the high frequency wave is shut in the direction orthogonal to the electric field 5a and attenuated sufficiently, then the wave is not outputted to the waveguide 4a. |
